A Hash Function Scheme for Key Management in UMTS MBMS

3GPP 33.246 proposes key management mechanism (KMM) to distribute security keys for universal mobile telecommunications system (UMTS) multimedia broadcast and multicast service (MBMS). KMM introduces extra communication overhead to UMTS. The previous study, key-tree scheme (KTS), resolves this issue for the IP multicast network. However, this scheme may not be so efficient while applied in UMTS MBMS due to lots of storage space and heavy multicast traffic introduced, which may decrease the QoS of UMTS MBMS. In this paper, we propose a more efficient scheme, Hash function scheme (HFS), to release both storage and communication overhead for KMM in UMTS MBMS. In this paper, we first modify the KTS to be applied in UMTS MBMS. Then we detail HFS. We prove the correctness of HFS. Our study shows that the proposed HFS can reduce both communication and storage overhead without damaging QoS of UMTS MBMS.